Conventionally it is known that fluororesins have excellent heat resistance, chemical resistance, weather resistance, water repellency, lubricating properties and electrical properties. Of the fluororesins having such properties, a fluorocopolymer obtained by the copolymerization of a fluoroolefin with a vinyl carboxylate, alkyl vinyl ether or the like is soluble in an organic solvent and forms a coating film having excellent properties, so that it has been used for coating building materials as a solvent-type highly weather-resistant paint.
In recent days, a fluorocopolymer having a hydrolyzable silyl group is known and because of its setting property by the humidity in the air, such is preferably used as a cold-setting paint. More specifically, a fluorocopolymer obtained by the copolymerization of a fluoroolefin, a vinyl carboxylate and a hydrolyzable silane monomer, as described in JP-B-6-104703 (the term "JP-B" as used herein means an "examined published Japanese patent publication"), a fluorocopolymer obtained by the copolymerization of a fluoroolefin, a vinyl ether and a hydrolyzable silane monomer, as described in JP-B-1-16405, and the like are known. These polymers are, however, accompanied with the problem that their coating films are easily stained by long-term outdoor exposure.
As a result of extensive investigations to obtain a cold-setting coating composition which has excellent weather resistance, processability, stain resistance and water resistance and is also excellent in adhesion to a substrate to be coated, it has been found that such a cold-setting coating composition can be obtained by using a specific fluorocopolymer different from the conventionally employed fluorocopolymer as described above, leading to the completion of the present invention. The fluorocopolymer used in the present invention has a constitution analogous to a fluorocopolymer which has so far been used as a highly weather-resistant sealant and is obtained by the copolymerization of a fluoroolefin, a (meth)acrylate ester and a hydrolyzable silane monomer, as described in JP-A-7-305018 (the term "JP-A" as used herein means an "unexamined published Japanese patent application), but the conventional fluorocopolymer of such a constitution has not been used as a paint or a coating composition.